Lawrence e



L. E. JOHNSON.

THREAD MEASURING DEVICE FOR SEWING MACHINES.

APPLICATI 1,320,330. I Patented Oct. 28,1919.

lxwezznhr: Lawrence E. Johnson,

LAWRENCE E. JOHNSON, 0F MELROSE, MASSACHUSETTS THREAD-MEASURING DEVICE FOR SEWING-MACIHNES,

' Specification of Letters Patent. A

Patented Oct. 2 8, 1919.

Application filed. March '7, 1919. Serial No. 281,869.

To all whom it may concern: 7

B it known that I, LAWRENQE E. OI-IN- son, a citizen of the United States of Amen ica, and a resident of Melrose, in the county of Middlesex and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Thread-Measuring Devices for Sewing-Machines, of which the following is a specification.

This invention relates to shoe sewing ma- The object of the present invention is to provide a means whereby the thread, when first inserted in the eyes in the forked thread guide, will be automatically placed in operative position relatively to the thread measuring device at the initial operation of the machine. r

The invention consists in providing the thread measuring lever with a V.-notched plate, the outer edge of which is cam-shaped and adapted to assist in automatically positioning an inaccurately placedthread in 1ts operative position in the V-notch of the thread measurer when. said measurer is moved upwardly relatively to th forked thread guide. V I

The invention further conslstsof certain novel features of constructionand arrangement of parts which will be readily understood by reference to the descriptionof the drawings and to the claims to he herelnafter given.

For the purpose of illustrating the in vention, one preferred form thereof is illustrated in the drawings, this form having been found to give satisfactory and reliable results, although it is to be understoodthat the various instrumentalities of which the invention consists can be variously arranged and organized, and that the invention is not limited to the precise arrangement and o-rganization of the lnstrumentalitles as herein shown and described, except as required by the scope of the appended claims.

Of the drawings I Figure 1 represents a transverse sectionof side of one of the side frames a sewing'machine embodying the principles of the present invention.

Fig. 2 represents a sectional detail showing the forked thiead'guiding member and the -thread"measuring memberin their ontreme positions relatively to each other in one direction and the thread in inoperative position above the thread measuring mem- .hi '3 represents a similar view. with said mem ers'in positions they assume when at the other extremefof their movements and showing the thread moved down on the outer ed e of the thread measurer, and

ig. 4 represents a similar view with the thread finally placed in operative position in the V-notch of the thread measurer.

Similar characters indicate like parts in i the several figures of the drawings.

In the drawings, 20 is the base of the machine adapted'to be secured to a column and having the side frames 21 provided with bearings for the revoluble shaft 23. The revolu'ble shaft 23 is rotated by a driving wheel secured to one end thereof. Interposed between the side frames 21 and keyed to the shaft 28 is the cam disk 27. To the inner 21 is secured the work support 28 which may be of any well-known construction.

The thread 6 is drawn from any suitable source of supplyand passes over a fixed rod 103 extending from one side frame 21 to the other, a pin 10 extending outwardly from this rod .103 positioning the thread 25 thereon and preventing it from slipping lengthwise thereof during the feeding of the work. The movement of thework in feeding is towardftlhe'left and the pin 104 is placed at the left of the thread .in that direction. The thread 2, then passes around a pm 105 secured to the thread lock cam lever 106 which is pivoted at 107 and has at its rear end a roller 108 in the cam path 109 formed in the right hand side of the disk 27.

The thread If passes from the pin 105 over a stationary pin 110 in the side frame 21 and then through slots in two downwardly extending arms 111 of a forked member 112. The thread 6 passes from one arm 111 to the other arm. 111 under a notched plate 113 projecting horizontally from the sideof th forward end of the lever 106. From the forked member 112 the thread If passes through a to prevent slipping hole 114 in the movable frame 62 to an eye on one of the side frames 21 and thence into the wax pot 116 secured to the side frames 21 in any well-known manner. To the front wall of the wax pot 116 is clamped, by means of the clamp screw 118, a support 119 provided with a sheave 121 around which the thread 25 passes through the liquid wax in said pot 116. y

The disk 27 is provided on its right hand face with a cam path 141 in which is positioned a roller 142 mounted on the end of the lever 143 pivoted at 144 and provided at its outer end with a pivoted block 145 between which end a guide Wall 145 is mounted the slidable member 112 having rack teeth 146 in one edge thereof.

The pivot 144 is provided with a gear 147 on its inner end the teeth of which mesh with the rack teeth 146 of the member 112. A plate 148 secured to the end of the lever 143 prevents the displacement of the mem ber 112.- This rack member 1121s provided with a lateral extension 149 to which is secured the presser'foot 150 of ordinary construction. The extension 149 forms a head to the slidable member 112 which is adapted to Contact with the upper face of the lever 143 to limit the downward movement of said member 112.'

Extending upwardly from the extension 149 and through the member 151 secured to the lever 143, is a rod 152 surrounded by a helical spring 153 which tends to retain the presser foot 150 in its normal position and against the tension of which said presser foot is adapted to be lifted. The lower end of the presser foot .150 has an operating face 158 parallel 'with the upper face of the work support 28.

It is obvious that when the slidable mem her 112 is moved transversely of the outer end of the lever 143 the lower face 158 of the presser foot 150 and the upper face of the work support 28 will remain constantly in parallelism in whatever position the presser foot may be while exerting a gripping pressure upon the work;

Secured to the pivot member 144 is an arm 159 adapted to be manually operated to adjust the presser foot 150 relative to the lever 143 and to accommodate it to varying thicknesses of material.

This is accomplished by the operator 1 moving the arm 159 and thereby turning the pinion 147, raising and lowering the presser foot at will.

When any work is placed upon the support 28, the-operator adjusts the presser foot in the manner just described so that it will rest upon the upper face of the work, after which it will be automatically adjusted as the material varies in thickness.

The machine is provided with a friction member as shown in U. S. Patent No.

1,177,249 issued March 28, 1916, said friction member being adapted to coact with the lever 159 atpredetermined times and thereby lock the pinion 147 and prevent any sliding movement of the member 112.

The notched plate 113 is adaptedto move in the forked end of the member 112, said plate being moved by the action of the cam path 109 on the lever 106 in the end'of which said plate is mounted. The cam path 109 throw adapted to oscillate the lever 106 at the proper time to measure off the given,

quantity ofthread for'the stitch, the plate 113 in doing this moving longitudinally of the slot in the end of the member 112.

. '75 is provided with a As the thread t in crossing this slot 7 passes beneaththe plate 113, it is obvious that if the slidable member 112 was always in the same position, a given lei'igth of thread would always be measuredby the.

oscillation of the lever 106 and the movement of the plate 113. i

It is desired, however, to measure off different lengths of thread for different thicknesses of material and this is readily accomplished by means of the slidable memher 112, it being self-evident that when the presser foot 150 is raised, the threadcarrying passages in the arms 1110f the member 112 are similarly raised to a new position corresponding with the thickness of the material and whenyin this raised position a greater quantiy of thread will be drawn from the source of supply by the movement of the plate 113 in the forked endof the member 112, the lowermost position of said plate being thesamc under all conditions.-

Itis obvious that this thread measuring device will operate after the presser foot 150 has returned into contact with the work. When the usual takeup device is operating,

the plate 113 will be in its highest position and the pin 105 will be in position to coact with the pm 110 to lock the thread to prevent it from being fed from the source of supply. I r

. he roller 108 is of less diameterthan the width of thecam path 109' and is in contact with the inner wall of said path only when the lever 106 is being moved about its pivot to measure the thread. The roller 108 never contacts with the opposite wall of said path. The pivot member 107 has secured to its outer end an arm to the end of which which is fastened to the frame 21, all as shown and described in U. S Patent 'No' 1,133,149 issued March 23, 1915. This' spring retains the pin 105 in contact with the pin 110 except during the thread measuring operation. I

As described in the aforesaid Patent No. 1,133,149, the pivot member 107 is revolubly mounted in an eccentric bushing in the accomplished by the locking pins 105 and V frame 21 towhich'it; is clamped by abolt when adjusted by the handle. ing the position of the pivot member 107 in this manner, the normal length of thread for each stitch may be regulated, while by means of the mechanism for positioning the slide 112 the supply of thread for various thicknesses of material may be automatically de'termined,-' the various lengths of thread measured off being proportionate to the thicknessof materialthrough which the thread is to be fed.

After the hook of theshuttle has carried the loop of thread to apoint where it should be dropped to encircle and bedrawn up with its companion thread to form astitch, the takeup lever is operated to put the proper stress upon the needle thread to effect this result. It is then necessary to lock this thread between the takeup and the thread supply (not shown) to prevent it from being drawn from the latter. This is 110, the cam path 109 being so constructed as to eifect this result at the proper time.

It will be seen that with this locking de-v ice 105110, the thread is positively held against movement without danger of the t-akeup stealing thread from the supply and failing to properly set the stitch.

The machine is provided with mechanisms for forming the stitch, feeding the work, forming the loop, all as fully described in Letters Patent of the United States No.

1,133,147 issued March 23, 1915, on which this application is an improvement. As

these mechanisms form no part of the pres- Y ent invention, no detailed description thereof is herein given.

The entire operation of the machine is substantially the same as that described in the U. S. Patent No. 1,177,249, the only novelty in the present invention-being the substitution of the notched finger 113 for the vcorrespending round pin shown in the patent just referred to.

In practice, considerable difficulty has been found to exist in the use of the pin 113 of the Patent No. 177,249 owing to the carelessness of the operators when inserting the thread 25 through the eyes'in the arms 111, 111. r

If care is taken by the operator to insert the thread 25, when said pin 113 is in the position corresponding to the position-of the plate 113 in Fig. 3, there would'be no difliculty but as a matter of fact the operators will in many cases, endeavor to insert the thread while the members 106, 112 are in the positions shown in Fig. 2 and consequently the thread being above the thread measuring pin or finger 113, the measuring of the thread will not be effected.

It is obvious, therefore, that it is desirable to provide a means whereby the thread 25 By adj ust will be automatically positioned beneath the thread measuring finger 113 when it has been inserted in the eyes of the arms 111, 111, at a point above said linger as shown in Fig. 2 of the drawings.

This is accomplished bysubstituting for the round pin heretoforeused, a plate 113 having a V-notch 161 in its under edge and having its outer edge 162 cam shaped or curved from a point 163 above the apex of the notch 161 to the lower end of the outer inclined wall 164 of said notch 161.

When the thread 6 is in the position shown in Fig. 2 above the plate 113 and in contact with the curved-edge 162 of said plate, it is obviousthat as soon as the lever 106 moves upwardly relatively to the member 112, the thread t will ride downthe curved edge 162 into the position shown in Fig. 3 of the drawings.

The extreme lower portion of the curved edge 162 is curved inwardly as at 165 and the pull upon the thread will cause said thread to be pulled over this curved portion 165 into the notch 161, in which position it will be acted upon by the plate or finger 113, exactly the same manner as described in the Patent No. 1,177,249 referred to.

It is self evident that with the V-notched plate 113 in use the thread 25 may be inserted in the thread guiding arms 111, 111, in any position of the machine and said thread will be automatically placed in operative position at the initial rotation of the shaft 23.

The plate 113 is provided with a shank 166 adapted to be driven into the lever 106 until the shoulder 167 thereon abuts theface of said lever.

The apex of the notch 161 is in vertical alinement with the eyes in the thread guiding arms 111, 111.

It is believed that the operation of this invention and its many advantages Will be fully understood without further description.

Having thus described my invention I claim 1. The combination of a pivoted cam-com trolled lever; a member thereon having an open ended slot in one end thereof adapted to guide a thread across said slot; a work support; a presser foot secured to said slidable member; and a reciprocating thread engaging member having a V-shaped notch therein and operating in said slot to pull a required length of thread from the supply.

2. The combination of a pivoted cam-controlled lever; a member carried thereby having an open ended slot in one end; a work support; a presser foot secured to said slotted member; means for guiding a thread across the slot of said slotted member; and a thread measuring device coacting with said slotted member and having a curved outer edge adapted in its initial movement to insure the placing of the thread in Working position beneath said device.

3. The combination of a pivoted cam-controlled lever; a member thereon having an open ended slot in one end thereof and adapted to guide a thread across said slot; a work support; a presser foot secured to said slotted member; and a reciprocating thread engaging member having an open ended notch in its lower edge and operating in said slot to pull a required length of thread from the supply, said reciprocating member having a curved outer edge extending from a point above the top of said notch t0 the lower end of the outer wall thereof.

4. Thecombination'of a pivoted cam-controlled lever; a member carried thereby having an open ended slot in one end; a work support; a presser foot secured to Slll slotted member; a thread measurlng device consisting in part of a plate reciprocable LAWRENCE E. JOHNSON.

- l/Vitnesses: i

lVAL'rER E. LoMBARn, f NATHAN C. LOMBARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, D. 0. 

